Double-source heat pump drying system with heat recovery device

Abstract

The utility model discloses a double-source heat pump drying system with a heat recovery device, which comprises a compressor, an outlet of the compressor is connected with an inlet of a high-temperature condenser, an outlet of the high-temperature condenser is connected with an inlet of a gas-liquid separator, and an outlet of the gas-liquid separator is respectively connected with an inlet of a low-temperature condenser and a cooling throttle valve. An outlet of the low-temperature condenser is sequentially connected with a dehumidification throttling valve and a low-temperature evaporator, a cooling throttling valve is connected with an inlet of the high-temperature evaporator, an outlet of the low-temperature evaporator and an outlet of the high-temperature evaporator are both connected with an inlet of the compressor, and the high-temperature evaporator, the low-temperature condenser and the high-temperature condenser are sequentially arranged in the channel in the air flowing direction. The two ends of the channel are connected with the drying chamber. The drying system disclosed by the utility model greatly improves the utilization rate of heat.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat pump drying, and particularly relates to a dual-source heat pump drying system with a heat recovery device. Background Technique

[0002] There are a wide variety of agricultural and special products in China, with a huge output. Since the newly harvested agricultural and special products have a high moisture content, they need to be dried in a proper way in time to obtain dried agricultural and special products and maintain a low moisture content for long-term storage. Traditional drying methods mainly include natural drying and drying in traditional drying rooms. Natural drying is easily affected by factors such as weather and climate, and the drying quality is unstable; traditional drying rooms use coal, oil, and gas combustion to provide heat, which is not environmentally friendly and has high energy consumption. Heat pump drying has the advantages of high efficiency, energy saving, good drying effect, and low drying cost, and has been applied to a certain extent in the drying of agricultural and special products.

[0003] A heat pump drying system consists of a heat pump unit and a drying chamber. During operation, the refrigerant absorbs sensible heat and latent heat from the hot air discharged from the drying chamber in the evaporator and then turns into vapor. After being compressed by the compressor, it enters the condenser to condense, and the heat in the working medium is transferred to the air; the hot air heated by the condenser is sent into the drying chamber to dry the drying object. The air at the outlet of the drying chamber of the traditional heat pump drying system is directly discharged into the environment without heat recovery treatment, resulting in heat waste. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a dual-source heat pump drying system with a heat recovery device to solve the problem of heat waste existing in the existing heat pump drying system.

[0005] The technical solution adopted by the utility model is that a dual-source heat pump drying system with a heat recovery device includes a compressor. The outlet of the compressor is connected to the inlet of a high-temperature condenser, the outlet of the high-temperature condenser is connected to the inlet of a gas-liquid separator, and the outlet of the gas-liquid separator is respectively connected to the inlet of a low-temperature condenser and a temperature-reducing throttle valve. The outlet of the low-temperature condenser is successively connected with a dehumidifying throttle valve and a low-temperature evaporator. The temperature-reducing throttle valve is connected to the inlet of a high-temperature evaporator. The outlets of the low-temperature evaporator and the high-temperature evaporator are both connected to the inlet of the compressor. The high-temperature evaporator, the low-temperature condenser, and the high-temperature condenser are sequentially arranged in a channel according to the air flow direction, and both ends of the channel are connected to the drying chamber.

[0006] The characteristics of the utility model also lie in that

[0007] A heat accumulator is arranged in the channel, and the heat accumulator is arranged between the inlet end of the channel and the high-temperature evaporator.

[0008] A second fan is arranged at the inlet end of the channel, and a first fan is arranged at the outlet end of the channel.

[0009] The drying chamber includes an inner layer, an outer layer is sleeved on the outer wall of the inner layer, a third fan is arranged at the top of the inner layer, a fourth fan is arranged at the bottom of the outer layer, and the two ends of the inner layer are communicated with the channel.

[0010] A through hole is arranged on the outer wall of the channel and between the high-temperature evaporator and the low-temperature condenser, a baffle is arranged on the channel, and the baffle cooperates with the through hole.

[0011] The baffle is arranged on the through hole.

[0012] One end of the baffle is connected to the inner wall of the channel, and the other end of the baffle is arranged at the center of the through hole.

[0013] The baffle is arranged in the through hole and the baffle passes through the center of the through hole.

[0014] The beneficial effects of the present utility model are as follows: The double-source heat pump drying system with a heat recovery device of the present utility model is provided with a heat accumulator. The heat accumulator can absorb the waste heat in the drying chamber to heat the air dehumidified by the high-temperature evaporator. When the temperature in the drying chamber is stable, the excess hot air is circulated into the interlayer of the drying chamber wall, thereby playing a role in heat preservation and insulation, greatly improving the utilization rate of heat and avoiding heat waste. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of Embodiment 1 of the double-source heat pump drying system with a heat recovery device of the present utility model;

[0016] Figure 2 It is a schematic structural diagram of Embodiment 2 of the double-source heat pump drying system with a heat recovery device of the present utility model;

[0017] Figure 3 It is a schematic structural diagram of Embodiment 3 of the double-source heat pump drying system with a heat recovery device of the present utility model.

[0018] In the figure, 1. Compressor, 2. High-temperature condenser, 3. Gas-liquid separator, 4. Low-temperature condenser, 5. Dehumidification throttle valve, 6. Low-temperature evaporator, 7. Cooling throttle valve, 8. High-temperature evaporator, 9. Heat accumulator, 10. First fan, 11. Second fan, 12. Third fan, 13. Fourth fan, 14. Drying chamber, 15. Baffle, 16. Channel, 17. Outer layer, 18. Inner layer, 19. Through hole. Detailed Embodiments

[0019] The present utility model will be described in detail below in conjunction with the drawings and specific embodiments.

[0020] Embodiment 1

[0021] The double-source heat pump drying system with a heat recovery device of the present utility model has a structure as Figure 1As shown in the figure, it includes a compressor 1. The outlet of the compressor 1 is connected to the inlet of a high-temperature condenser 2. The outlet of the high-temperature condenser 2 is connected to the inlet of a gas-liquid separator 3. The outlet of the gas-liquid separator 3 is respectively connected to the inlet of a low-temperature condenser 4 and a temperature-reducing throttle valve 7. The outlet of the low-temperature condenser 4 is successively connected with a dehumidifying throttle valve 5 and a low-temperature evaporator 6. The temperature-reducing throttle valve 7 is connected to the inlet of a high-temperature evaporator 8. The outlets of the low-temperature evaporator 6 and the high-temperature evaporator 8 are both connected to the inlet of the compressor 1. Then, a closed loop one composed of the compressor 1, the high-temperature condenser 2, the gas-liquid separator 3, the low-temperature condenser 4, the dehumidifying throttle valve 5, and the low-temperature evaporator 6 is formed, and a closed loop two composed of the compressor 1, the high-temperature condenser 2, the gas-liquid separator 3, the temperature-reducing throttle valve 7, and the high-temperature evaporator 8 is formed. These two closed loops constitute a heat pump cycle system. The heat pump cycle system uses azeotropic refrigerant composed of R134a and R22. The high-temperature evaporator 8, the low-temperature condenser 4, and the high-temperature condenser 2 are successively arranged in a channel 16 according to the air flow direction. Both ends of the channel 16 are connected to a drying chamber 14 for drying agricultural and special products. A heat accumulator 9 is arranged in the channel 16, and the heat accumulator 9 is used to store heat for the air flowing out of the drying chamber 14. The heat accumulator 9 is arranged between the inlet end of the channel 16 and the high-temperature evaporator 8. The high-temperature evaporator 8 is used for dehumidification, that is, the air in the drying chamber 14 enters the channel 16 and first flows through the heat accumulator 9 for heat storage, then reaches the high-temperature evaporator 8 for dehumidification, and then flows through the heat accumulator 9 again for primary preheating, reaches the low-temperature condenser 4 for secondary preheating, and finally is heated by the high-temperature condenser 2 and flows into the drying chamber 14, forming a closed loop of air circulation.

[0022] A second blower 11 is arranged at the inlet end of the channel 16, and the second blower 11 is used to draw the air in the drying chamber 14 into the channel 16. A first blower 10 is arranged at the outlet end of the channel 16, and the first blower 10 is used to draw the air in the channel 16 into the drying chamber 14 to make the air circulate.

[0023] The drying chamber 14 includes an inner layer 18. The outer wall of the inner layer 18 is sleeved with an outer layer 17. A third blower 12 is arranged at the top of the inner layer 18, and a fourth blower 13 is arranged at the bottom of the outer layer 17. The inner layer 18 is communicated with both ends of the channel 16. When the temperature and humidity in the drying chamber 14 are both stable, the third blower 12 is turned on to blow the hot air in the drying chamber 14 into the sandwich layer (between the inner layer 18 and the outer layer 17), so that a certain amount of heat can be maintained in the sandwich layer, which can play a role in heat preservation and insulation for the drying chamber 14 to a certain extent. The main function of the fourth blower 13 is to accelerate the gas exchange rate between the whole system and the external environment. When the humidity is relatively high, part of the air with a higher moisture content can also be released to the external environment through the third blower 12 and the fourth blower 13.

[0024] A through hole 19 is provided on the outer wall of the passage 16 and between the high-temperature evaporator 8 and the low-temperature condenser 4. A baffle 15 is disposed on the through hole 19. The end of the baffle 15 is connected to the inner wall of the through hole 19, and the baffle 15 completely blocks the through hole 19.

[0025] The working principle of the dual-source heat pump drying system with a heat recovery device of the present utility model is as follows: The superheated refrigerant vapor discharged from the compressor 1 enters the high-temperature condenser 2. Most of the high-boiling refrigerant condenses and releases heat to form a two-phase refrigerant liquid, and then enters the gas-liquid separator 3 and is divided into two paths: The high-pressure refrigerant vapor of the low-boiling refrigerant enters the refrigerant inlet of the low-temperature condenser 4 as the working fluid. This refrigerant vapor is condensed into a saturated or subcooled refrigerant liquid in the low-temperature condenser 4. This saturated or subcooled refrigerant liquid enters the dehumidification throttle valve 5 to throttle and cool into a two-phase refrigerant fluid, and then enters the low-temperature evaporator 6 to absorb heat and become a saturated or superheated refrigerant gas; The other path of saturated high-boiling refrigerant liquid enters the cooling throttle valve 7 as the working liquid to throttle and cool into a two-phase refrigerant gas, and then enters the high-temperature evaporator 8 to absorb heat and form a saturated or superheated refrigerant gas. The two refrigerant gases are mixed and jointly enter the compressor 1 to complete the cycle; The air in the drying chamber 14 forms a closed cycle in the passage 16, that is, the hot air in the drying chamber 14 is driven by the second fan 11 to flow through the regenerator 9 to store heat and then flow through the high-temperature evaporator 8 for dehumidification. After dehumidification, the air flows through the regenerator 9 again to absorb the heat therein, and flows to the low-temperature condenser 4 under the drive of the second fan 11 to absorb the refrigerant heat therein, and then passes through the high-temperature condenser 2 to absorb the heat of the high-temperature refrigerant vapor therein. Finally, the dried hot air is driven by the first fan 10 to return to the drying chamber 14 for drying to complete the cycle. The closed-cycle system has the best heating effect.

[0026] Embodiment 2

[0027] The difference from Embodiment 1 is that the baffle 15 is not disposed on the through hole 19. Instead, one end of the baffle 15 is connected to the inner wall of the passage 16, and the other end of the baffle 15 is disposed at the center of the through hole 19. That is, the through hole 19 is divided into two parts. The first part is for the air flowing from the drying chamber 14 into the passage 16 to flow out of the passage 16, and the second part is for the external air to flow into the passage 16. Then, the air in the drying chamber 14 can exchange gas with the outside world to form an open-cycle system. The specific working process of this embodiment is as follows: The hot air in the drying chamber 14 directly discharges to the outside through the first part of the through hole 19 after passing through the regenerator 9 and the high-temperature evaporator 8. The fresh air from the outside passes through the second part of the through hole 19, is preheated through the low-temperature condenser 4 and the high-temperature condenser 2, and then is blown into the drying chamber 14 by the first fan 10 to dry the material. The open system has the best dehumidification effect.

[0028] Embodiment 3

[0029] The difference from Example 1 is that the baffle 15 is not disposed on the through hole 19, but the baffle 15 is disposed within the through hole 19 and the baffle 15 passes through the center of the through hole 19. That is, the through hole 19 is divided into two parts. The first part is for a part of the air flowing from the drying chamber 14 into the channel 16 to flow out of the channel 16, and the second part is for the external air to flow into the channel 16. This enables the air in the drying chamber 14 to exchange gas with the outside world. At the same time, there is a gap between the end of the baffle 15 located within the channel 16 and the inner wall of the channel 16, so that another part of the air flowing from the drying chamber 14 into the channel 16 can continue to flow through the channel 16 through this gap, mix with the outside air, and then pass through the low-temperature condenser 4 and the high-temperature condenser for preheating, and then be blown into the drying chamber 15 by the first fan 10 to dry the material. This embodiment forms an open-close combined circulation system, and the open-close combination can ensure a relatively fast temperature rise while having a high dehumidification efficiency.

Claims

1. Dual-source heat pump drying system with heat recovery device, characterized in that: The invention comprises a compressor (1), wherein the outlet of the compressor (1) is connected to the inlet of a high-temperature condenser (2), the outlet of the high-temperature condenser (2) is connected to the inlet of a gas-liquid separator (3), the outlet of the gas-liquid separator (3) is respectively connected to the inlet of a low-temperature condenser (4) and a cooling throttle valve (7), the outlet of the low-temperature condenser (4) is sequentially connected to a dehumidification throttle valve (5) and a low-temperature evaporator (6), the cooling throttle valve (7) is connected to the inlet of a high-temperature evaporator (8), the outlet of the low-temperature evaporator (6) and the outlet of the high-temperature evaporator (8) are both connected to the inlet of the compressor (1), the high-temperature evaporator (8), the low-temperature condenser (4) and the high-temperature condenser (2) are sequentially arranged in a channel (16) according to the air flow direction, and both ends of the channel (16) are connected to a drying chamber (14); A heat accumulator (9) is arranged in the channel (16), and the heat accumulator (9) is arranged between the inlet end of the channel (16) and the high-temperature evaporator (8).

2. The dual-source heat pump drying system with a heat recovery device according to claim 1, characterized in that: The inlet end of the channel (16) is provided with a second fan (11), and the outlet end of the channel (16) is provided with a first fan (10).

3. The dual-source heat pump drying system with a heat recovery device according to claim 1, characterized in that: The drying chamber (14) comprises an inner layer (18), the outer wall of the inner layer (18) is provided with an outer layer (17), a third fan (12) is provided at the top of the inner layer (18), a fourth fan (13) is provided at the bottom of the outer layer (17), and the inner layer (18) is connected to both ends of the channel (16).

4. The dual-source heat pump drying system with a heat recovery device according to claim 3, characterized in that: Hot air can be stored between the outer layer (17) and the inner layer (18).

5. The dual-source heat pump drying system with a heat recovery device according to claim 1, characterized in that: A through hole (19) is provided on the outer wall of the channel (16) and is located between the high-temperature evaporator (8) and the low-temperature condenser (4). A baffle (15) is provided on the channel (16), and the baffle (15) cooperates with the through hole (19).

6. The dual-source heat pump drying system with a heat recovery device according to claim 5, characterized in that: The baffle (15) is arranged on the through hole (19).

7. The dual-source heat pump drying system with a heat recovery device according to claim 5, characterized in that: One end of the baffle (15) is connected to the inner wall of the channel (16), and the other end of the baffle (15) is arranged at the center of the through hole (19).

8. The dual-source heat pump drying system with a heat recovery device according to claim 5, characterized in that: The baffle plate (15) is arranged in the through hole (19), and the baffle plate (15) passes through the center of the through hole (19).

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